White matter microstructure and local coherence of functional MRI in major depression

Introduction Anhedonia is a loss of pleasure and interest in activities and a core symptom of major depressive disorder (MDD). Diffusion tensor imaging studies show evidence for white matter (WM) alterations in the superior longitudinal fasciculus (SLF) of patients with MDD, already in the early stage of illness. SLF fibers extend from the parietal lobe to prefrontal regions that are important for attention, motivation, decision-making and reward processing. Objectives The present study focuses on the relationship between WM-integrity and anhedonia in patients with MDD. We hypothesize that WM-alterations are present in the SLF of depressed patients with motivational anhedonia. Methods Thirty-nine patients with MDD and 19 healthy controls matched for age and gender underwent diffusion-weighted magnetic resonance imaging. Voxel-wise statistical analysis of fractional anisotropy (FA) data was performed using FSL-Tract-Based Spatial Statistics (TBSS) software. Whole brain voxel-wise comparison in local coherence (LCOR), a measurement of resting state fMRI connectivity strength between a given voxel and the neighbouring areas in the brain, were compared between patients and healthy controls. We used the sum value of item 1 and 7 of the Hamilton rating Scale for depression (HAM-D) and the CORE non-interactiveness value to assess motivational anhedonia. Results TBSS-analyses revealed reduced FA in the left SLF of depressed patients and we found a correlation with motivational anhedonia and LCOR in temporo-parietal regions of depressed patients. Conclusions These findings suggest that WM-alterations in the SLF might be associated with motivational aspects of anhedonia and predict motivation of reward in MDD. Disclosure of Interest None Declared

Introduction: Childhood family income is a powerful predictor of academic achievement and mental health.Here, we ask whether children living in poverty-those whose family incomes are not sufficient to meet their material needs-who beat the odds by succeeding academically are subsequently either protected from, or more at risk for, internalizing disorders.Prior research indicates that children in poverty with better academic performance and more depressive symptomatology tend to have higher temporal coupling between lateral frontoparietal network (LFPN; supports executive functions) and Default Mode Network (DMN; supports internally-directed thought) than lower-performing children in poverty, in direct contrast to the pattern observed for children above poverty.Thus, an open question is whether this pattern of connectivity adaptive for children in poverty has maladaptive longterm consequences, particularly for mental health.Objectives: In this pre-registered study, we analyzed concurrent data from 8,091 children (1,307 in poverty) in the ABCD study at baseline (ages 9-10y).We performed linear mixed effects models to investigate whether both higher LFPN-DMN connectivity and grades are linked to more internalizing symptoms concurrently, and whether this differs for children above and below poverty.Methods: We performed linear mixed effects models to investigate whether both higher LFPN-DMN connectivity and grades are linked to more internalizing symptoms concurrently, and whether this differs for children above and below poverty.
Results: We found that higher grades were associated with fewer internalizing symptoms for both children above and below poverty; this association was stronger for children below poverty.In addition, LFPN-DMN connectivity showed a significant negative correlation with internalizing symptoms at this age.However, when looking at internalizing symptoms separately -that is, anxiety/ depression, withdrawal/depression, and somatic symptoms -we found that higher LFPN-DMN connectivity for children below poverty was associated with higher withdrawal/depression symptoms, but fewer somatic symptoms, pointing to a dissociation in what pattern of brain connectivity is most adaptive for the development of internalizing symptoms vs. physical health.These somatic symptoms highlight potential maladaptive consequences of resilience for children growing up in unequal structural conditions.Conclusions: This research has important implications for supporting children in poverty by illuminating mechanisms for, and potential maladaptive consequences of, their resilience in academic contexts.

EPP0879
White matter microstructure and local coherence of functional MRI in major depression S. Breit1,2 *, N. Denier 1,2 , N. Mertse 1,2 , S. Walther 1,2 , A. Federspiel 2 , R. Wiest3 and T. Bracht 1,2 Introduction: Anhedonia is a loss of pleasure and interest in activities and a core symptom of major depressive disorder (MDD).Diffusion tensor imaging studies show evidence for white matter (WM) alterations in the superior longitudinal fasciculus (SLF) of patients with MDD, already in the early stage of illness.SLF fibers extend from the parietal lobe to prefrontal regions that are important for attention, motivation, decision-making and reward processing.Objectives: The present study focuses on the relationship between WM-integrity and anhedonia in patients with MDD.We hypothesize that WM-alterations are present in the SLF of depressed patients with motivational anhedonia.Methods: Thirty-nine patients with MDD and 19 healthy controls matched for age and gender underwent diffusion-weighted magnetic resonance imaging.Voxel-wise statistical analysis of fractional anisotropy (FA) data was performed using FSL-Tract-Based Spatial Statistics (TBSS) software.Whole brain voxel-wise comparison in local coherence (LCOR), a measurement of resting state fMRI connectivity strength between a given voxel and the neighbouring areas in the brain, were compared between patients and healthy controls.We used the sum value of item 1 and 7 of the Hamilton rating Scale for depression (HAM-D) and the CORE non-interactiveness value to assess motivational anhedonia.
Results: TBSS-analyses revealed reduced FA in the left SLF of depressed patients and we found a correlation with motivational anhedonia and LCOR in temporo-parietal regions of depressed patients.Conclusions: These findings suggest that WM-alterations in the SLF might be associated with motivational aspects of anhedonia and predict motivation of reward in MDD.

EPP0880
Relationship between neural network structure and temperament/personality traits in healthy subjects Introduction: Cloninger divides personality into temperament and character, proposing that temperament is innate and character is shaped by environment.With the development of noninvasive methods for measuring central nervous system activity, there have been many attempts to test personality theories using neuroscientific research methods.Thus, the use of neuroscience to examine existing theories of personality will enable a review of these theories and may lead to the formulation of new theories of personality.Objectives: The purpose of this study was to investigate the biological factors underlying temperament and personality development in healthy adults by analyzing neural networks in the brain using resting-state functional magnetic resonance imaging.Methods: The study was conducted after obtaining prior approval from the Ethics Committee of Kanazawa Medical University.Eighty-one healthy subjects who consented to the study after explaining the purpose and methods were imaged with a 3T MRI scanner in the resting state, and statistical image analysis was performed using the CONN toolbox.Personality and temperament were assessed using the temperament personality test based on Cloninger's 7-dimensional model of personality.Results: Five types of neural networks were extracted by independent component analysis, including Salience, Default mode, and Language.Regression analysis revealed a significant relationship between the functional connectivity of the networks and temperament/personality traits.Conclusions: We were able to observe the functional connectivity of representative neural networks from the data of healthy subjects, suggesting that individual differences in the degree of functional connectivity of neural networks may be related to the individual characteristics of temperament and personality of the subjects.

Disclosure of Interest: None Declared
Others 05 EPP0881 Perception of psychiatry among non-psychiatric physicians: a tunisian study Introduction: Psychiatry is often perceived "different" by other medical professionals as well as by the general population.This perception of "difference" may give rise to stigma toward both patients with psychiatric disorders and mental health professionals.Objectives: The aim of this study was to investigate the attitudes of non-psychiatric and their perception of psychiatry and mental disorders.Methods: It was a cross-sectional, descriptive and analytical study, conducted among Tunisian undergraduate and graduate nonpsychiatric physicians.Data were collected during September and October 2022, through an anonymous online questionnaire, spread throughout social media (Facebook), using the Google Forms® platform.We used the "Attitude toward Psychiatry-30" (ATP-30).Results: A total of 168 participants completed the questionnaire.Among them, 81 (48,2%) were undergraduate and 87 (51,8%) were graduate doctors.Their mean age was 26,4AE 4.4 years, with a sexratio (F/M) of 3.4.Among doctors, 79,2% had overall favorable attitudes toward psychiatry but only 38,2% among the undergraduate considered psychiatry as a potential career choice.Psychiatry was considered as an unscientific and imprecise specialty by 20,3%; while 35,7% considered it as the least exciting.The total score ATP-30 increased significantly with age (p= 0.023).It was significantly higher in those with psychiatric history (p=0.01).Conclusions: Our study showed a dissonance between favorable perception of psychiatry and the choice of psychiatry as a potential career.Therefore, it is crucial to identify factors that potentially account for this dissonance and enhance enthusiasm among undergraduate doctors as the shortage of psychiatrists may influence mental healthcare.

EPP0882
Quality in Psychiatric Care in a global perspective